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WATER JET PROPULSION FOR STBAMSHIPS. No. 498,572. Patented May 30, 1893.

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WATER JET PROPULSION FOR STEAMSHIPS.

No. 498,572. Patented May 30, 1893.

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UNITED STATES PATENT OFFICE.

FREDERIC WILLIAM RICHARDSON, OF WVEST HARTLEPOOL, ENGLAND,

ASSIGNOR TO THE TUBULAR TWIN SCREW AMIDSHIPS PROPULSION COMPANY, LIMITED.

WATER-JET PROPULSION FOR STEAMSHIPS.

SPECIFICATION forming part of Letters Patent No. 498,572, dated May 30, 1893. Application filed October 24, 1892. Serial No. 449,836. (No model.) Patented in England February 4, 1887, No. 1,764.

To all whom it may concern.-

Be it known that I, FREDERIC WILLIAM.

RICHARDSON, a subject of the Queen of Great Britain, residing at West Hartlepool, in the county of Durham, England, have invented certain new and useful Improvements in Water-Jet Propulsion for Steamships, (for which I have obtained Letters Patent in Great Britain, No. 1,764, bearing date February 4, 1887;) and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

My invention, which relates to an improved method of applying a propelling power to ships, has for its object to obtain such power by the employment of hydraulic or water-jet pressure applied about amidships from water channels provided in the inside bottom of the vessel, and may be applied as an auxiliary force to the propelling power derived from paddle wheels or the usual screw propellers, but principally in substitution of these modes of propulsion.

The advantages derived from my invention are a steady propelling force which may be relied on in all states of the water and with vessels of light draft and which is capable of. propelling the vessel straight ahead or straight astern with equal facility, or of maneuvering or even turning the vessel round on its center.

If my improved mode of propulsion be employed independently of paddle wheels or ordinary screws, a reduction and simplification of the internal machinery of the vessel is effected, all liability of the engines racing is obviated, and much of the vibration and side wash inseparable from the action of screws and paddle wheels is avoided.

In carrying out my invention for obtaining the hydraulic or water-jet pressure, one or more chambers forming water channels are provided about amidships on the inside bottom of the vessel forming water channels communicating at either end with the water in which the slip floats; for maneuvering purposes to such water channels are provided, one on each side of the keel and preferably as wide of the keel as possible to obtain greater maneuvering power, their positions being parallel to each other and to the keel; each water channel is curved or inclined so that each end dips down through the skin of the ship and communicates with the sea or water supporting the vessel, and the center rises high enough up into the inside bottom of the ship to form a chamber in which a two or three bladed screw propeller can be to tated by a shaft extending to and driven by one of the engines of the ship; each screw propeller, where more than one is provided, is preferably driven independently so as to be under separate control for maneuvering purposes.

In order. that my invention may be fully understood and readily carried into effect, I will now proceed to describe the same with reference to the annexed drawings, in which Figure 1 illustrates a transverse section of avessel taken about amidships. Fig.2 is a sectional view taken on line X X of Fig. 1 with screw shaft set horizontally. Fig. 3 being a similar view to Fig. 2 with screw shaft set at an angle as and for the purpose hereinafter explained.

a a are chambers forming the water channels and are preferably cylindrical, ineach chamber a is provided a screw propeller b rotated by means of a shaft 0 extending through to the engines of the ship.

The propelling power is obtained as follows:The action of the screw propeller b rotating in the chamber a expels the water therefrom through what may be termed the outlet end, the influx of water into the chamber or water channel a is maintained at a velocity due to the "difference of level between the surface of the water and the position of the screw propeller plus the velocity due to the suction of the screw when revolving at a sufficiently high speed to cause a partial vacuum in the chamber a on the intake side of the screw, the thrust available for propulsion being the difference of pessure between one side of the screw and the other multiplied by the sectional area of the jet.

' In Fig. 1, and more particularly in Fig. 2, the screw shaft is shown in a horizontal position as adapted to take its rotary motion from a vertical engine, but it is found in practice that when so placed with the screw rotating in a vertical plane that the water is thrust forward in a horizontal direction and consequently impinges against the upper side of r the output end of the tube or chamber a sufficiently to meet a resistance which sensibly reduces the efiective work of propulsion due to the action of the screw. I therefore prefer, where the general construction of the vessel admits of it, to set the screw shaft at the same angle as the center of the output end of the tube A as shown in Fig. 3, which brings the plane of rotation of the screw 17 square to the output end of the tube by which the water is thrust forward from the screw in the direction of the least resistance and a maximum of effective work is obtained for propelling the vessel. The outflow of the water is still further facilitated by setting the outflow end of the tube a at a less incline than the intake end, say as an example at angles of eleven and one-quarter degrees and fifteen degrees respectively, as illustrated by the axes 4 land 5 5 of the tubes shown in Fig. 3, the effect being similar to using a tapered tube in which the small end is at the position of the screw. Moreover, by inclining the axis 5 5 of the outlet tube less than the axis of the inlet tube, the reaction of the escaping water on the mass of water beneath the vessel takes place at a more advantageous angle, since the effect desired is to push the vesse ahead.

The number of screw propellers provided in chambers forming water channels through the inside bottom of the vessel as-hereinbefore described may be varied to correspond with the general design and requirements of the vessel, but where two screws are provided one on each side of the keel as illustrated in the drawings and worked from separate engines, by reversing one or both of the screw propellers or by altering their relative speed the ship can be turned round on its center or may be otherwise maneuvered much more eifectually than is possible by any means at present in use.

Having now particularly described and ascertained the nature of my said invention and in what manner the same is to be carried into effect, I declare that what I claim is- A device for propelling ships, comprising one or more bent tubes for admitting and ejecting water, the said tubes opening downward through the bottom of the vessel, and having the front portion set at a greater angle to the load water line than the rear portion; and the axis of the bent tube in a plane approximately parallel to the vertical plane of the keel; and a screw propeller set near the upper portion of said tube, substantially as and for the purposes described.

In testimony whereof I aflix my signature in presence of two witnesses.

FREDERIO WILLIAM RICHARDSON.

Witnesses:

GEORGE JAMES OLARKsoN, EDWARD THOMAS ELooA'r. 

